DiHydrogen Oxide
by Yaoi's Consort
Summary: Sherlock's a little too curious about this one human. He's never seen him, but his fishing techniques are bizarre.


"Bored." Tug. Fwish!

"Booored." Tug. Fwish!

"Booooooored." Tug. Fwish!

"Sherlock, stop playing with the humans. We aren't even supposed to be in this part of the ocean."

"Well, I'm _bored._" Another tug and the line shoots up. Above them the boat shifts, and muffled cursing is heard through the water even as Sherlock directs a pout in Mycroft's direction. "And humans are so much more interesting than anyone down here."

Mycroft's tail swishes side to side, the steel-coloured scales flashing dully in the late afternoon sun. it's the only outward sign showing just how irritated he is. He presses his fingers to his forehead, trying to smooth the wrinkles that Sherlock is responsible for. "Honestly, Sherlock, I—"

"Just look." Sherlock pulls lightly on one of the many hooks that invade the water. It shoots up, and once it passes through the barrier separating water and air, there's a moment's silence before the boat above them rocks, and muted shouting travels through the water. "This one has a hair trigger, as well as an extremely short temper. I've only done that four times. While this one," he tugs a few times on another line, also coming from the same boat, "is smart enough to know the difference between a nibble and a bite. Obviously more experienced, and because the two share a boat and considering how quickly the short-tempered one has calmed down, I'm thinking related, possibly father and son."

As Sherlock had said, the din had stopped, And Mycroft could feel sulkiness almost ooze from the boat as the line was put in the water again. "Yes, Sherlock, it's all very interesting, but—"

"And these!" He motions to a few hooks, all arranged in a neat line. "This fellow, for there's only one person in the boat, put down multiple lines, all baited differently and at different depths to increase the variety of his quarry. This one, " he indicates a line with a little brown worm waving sadly in the current, "is aimed toward the more common fish, such as cod or bass, and this," a slightly smaller hook with false bait, position higher in the water, "is for catching bait fish. Oh! And this," he swims down a bit and Mycroft trails behind, spotting a large green lure with multiple hook sprouting off it, "this is for larger fish like Pollock or red bream, "

"Sherlock, please, if you don't mind, we—"

"Oh, but I do mind." A mischievous light comes to his eyes, before fading to a pensive look as he glanced behind Mycroft. The older of the pair turned around, trying to determine what had captured Sherlock's attention _now_. The fishing boats were loosely grouped together more than likely an unconscious decision; it reminded Mycroft of the large shoals of fish that would swim through the ocean. Such social creatures, humans were, so fearful and petty. Grouping together would do no good in a situation like this. You can't catch a fish in such conditions, not with so much noise and so many boats. Might as well be fishing for rubbish.

Sherlock started moving in the direction of the reef, and Mycroft followed, trying to puzzle out what exactly he was supposed to be seeing.

When they were miles from the cluster of fisherman, Sherlock made a grab at the water, and Mycroft caught sight of a thin, shimmering line. He sucked in a breath; he'd never been unable to tell where a fishing line was. That was why the Mer were rarely caught, and how they had been able to avoid capture. Glancing up, he noted that there were no boats directly above them. He came back to the situation as Sherlock began talking.

"This one is immensely different from the rest, or from any humans I've encountered. The only reason I found it was because the hook got tangled in my hair." He twirled the wickedly sharp hook between his fingers, spinning it round and round. "It's finer than anything any of the others have, and the line is mottled with different shades of blue, rather than clear, hiding it better in the water. And," he gave a tug, then yanked the line hard, moving his hands side-to-side like a fish caught and attempting to escape. Mycroft gave a shout of alarm; he'd known Sherlock to be risky, but this? This was madness!

But as he continued to do so, pulling furiously and for all the world Above seeming to be a fish, there was no responding yank from the other end. Letting go, he grinned at Mycroft, hair tussled and breathing a little hard. "He can tell the difference between me and a fish."

"Are you sure he isn't just sleeping?" Mycroft asked, ever the skeptic.

"Of course I am. Had he been sleeping, his pole would already be in the water and he'd have awoken from the racket it would cause." Sherlock replied, waving his hand dismissively. "I observed as a fish get caught the hook, and he was pulled right up. Oh, but isn't this exciting, Mycroft!" He suddenly exclaimed, his eyes shining with unusual fervor that Mycroft had never seen before. "His line is invisible to us, he doesn't use bait and yet he manages to attract fish to his hook and bite down, and he's reasonably good at the sport! Yesterday, I put on a variety of fish, and they all told me it was as though there was some force drawing them to it, enticing them. And, oh, Mycroft, he let them go! They were perfectly sized and he put them back! Oh, he's an anomaly, Mycroft, a marvel!" He gleamed with childlike excitement.

Mycroft let out a long-suffering sigh, massaging his head. As much as this piqued his interest, to show Sherlock that would make him smug beyond reasoning. "One of these days, Sherlock, you're going to try and make contact or get caught and we'll have to deal with the frenzy of mermaid catchers and private collectors that follow."

"Well, it would certainly make things more interesting."

Mycroft sighed again, changing the topic before he could be bothered to get his temper up. "So just where is the boat this line leads to?"

Sherlock grinned in a way that made Mycroft squirm ever so slightly, too knowing for his liking. "For that, I need a vi-volunteer. Molly!"

His voice resonated through the water, and Mycroft's persistent headache evolved into a pounding migraine. He waited for his ears to stop pounding before he started to talk. "Honestly, Sherlock, you need to learn some control." He stuck a finger in his ears, attempting to stop the echo in his head. "At least enough to keep your voice from affecting those around you."

"Control lessons are boring."

"Everything seems to be boring to you."

"Because almost everything is. Too predictable and easy for my tastes. I think I see Molly. Molly! Over here!"

Slowly, a shape comes into focus gradually coming towards them. In any other scenario Mycroft would probably have driven it away. But this is Molly we're talking about.

Molly is a nurse shark, and utterly smitten with Sherlock. Mycroft felt sorry for the poor girl; Sherlock would have her bring him things, be it fish or, more popular, human artifacts that were almost everywhere. He would conduct experiments on them; the majority broken and unusable, but on occasion there would be something that would work, like a farseer or a timekeeper.

Mycroft has had to study human runes, as rare as it is to find any that survive the torrent of the ocean, the flimsy pulpish substance and ink they write in so very fragile. Sherlock writes in his records in human runes, and Mycroft, though he is loathe to admit it, is not as good at interpreting them as Sherlock is. Mycroft doesn't know how he became so adept with so little material, but he has a sneaking suspicion that Sherlock has had too many visits to the surface.

But oh, poor, poor girl; if she was ever hesitant, it never took more than a compliment of her fins or a touch to brush a lamprey off her stomach from Sherlock and she was putty in his hands again.

Mycroft looked skeptically at the gleaming little hook at the end of the mysterious line. "Sherlock, I'm not sure that can hold her."

"Oh, it's fine, Mycroft." Molly's voice is light, a common characteristic of nurse sharks, and sounds slightly bubbly, like the speak of all fish. "The line can hold me, and the man up there's a nice bloke. After he got over the shock of seeing me on his line, he worked the hook out of my mouth quick enough."

"Steady hands, possibly a surgeon. The quick recovery indicates he's dealt with significant trauma before, perhaps multiple times. Possibly some kind of marine biologist, but then why would he be fishing? He doesn't tag the fish he catches, I checked, so is it simply a hobby? And—"

"Sherlock, I believe that's enough for now. Molly, if you would be so kind?" Mycroft interrupted, now more intrigued than before. An anomaly, just as Sherlock said.

"Right away." Molly bit down on the hook, careful not to take Sherlock's fingers into her mouth. Sherlock jerked his hand away, removing it from the line of danger and sinking the hook into the flesh of Molly's cheek at the same time. Molly flinched at the slight pain, her eyes rolling back momentarily. Tentively, she tugged, and almost immediately the line puled taut, dragging Molly east.

Sherlock grinned at Mycroft, eyes overbright and gleaming.

"Now we follow."


End file.
